Fixing piece for a windscreen wiper

ABSTRACT

The invention is based on a mounting part ( 10 ) of a windshield wiper, having a receiving opening ( 12, 46 ) for a wiper shaft ( 44 ) at one end, and forming a part ( 14 ) of a fold-away hinge at the other end, and being formed from a flat sheet metal ( 28 ) by deep-drawing, punching and bending and having a u-shaped cross-section profile ( 20 ) and a spring mount ( 16 ).  
     It is proposed to form the spring mount ( 16 ) by deep-drawing from a sidewall ( 24 ) of the u-shaped cross-section profile ( 20 ).

BACKGROUND INFORMATION

[0001] The present invention is based on a mounting part for awindshield wiper according to the definition of the species in claim 1.

[0002] Known windshield wipers have a wiper arm, which is made up of adriven mounting part and a hinge member that is connected to it by ahinged joint and has a wiper rod. A wiper blade is pivoted at the freeend of the wiper rod. The wiper blade is guided across the vehiclewindshield during the swivel motion of the windshield wiper, anextension spring prestressing the fold-away hinge, so that the wiperblade is pulled toward the vehicle windshield.

[0003] The extension spring is accommodated in the u-shapedcross-section profile of the articulated part and is suspended on thearticulated part by one end using a cross-pin. By its other end, theextension spring is attached to a spring mount on the mounting part, viaa c-shaped clip. In known mounting parts, this spring mount is eitherpreformed or formed by a rivet pin. In one variant, for instance,mounting parts, designed as sheet metal form parts, use a pin as springmount. During manufacture, this is pressed into holes in the sidewallsof the u-shaped cross-section profile of the mounting part, and thenriveted. In contrast to a one-piece mounting part, this requiresadditional production time for the installation and production of theadditional components.

[0004] The spring mount is exposed to relatively high forces by theextension spring. In the working position, or fold-away position, theseforces also come to bear from different directions, with a 90°difference, for example, resulting in a relative movement between theextension spring or the c-shaped clip and their mountings. To achievesufficiently high strength, the mounting pin at the mounting part isusually made from a different material than the sheet metal bentcomponent. However, when joining different materials, the danger ofcontact corrosion exists in the interconnecting region.

[0005] In addition to a part of the fold-away hinge and a spring mount,the mounting part also has a mounting region on the opposite end bywhich the wiper arm is rigidly, but detachably connected to a wipershaft. The mounting region is designed as a shaft-hub-connection and isformed by a receiving opening having an inner cone, into which the freeend of the wiper shaft, which is provided with an approriate outer cone,projects. The two parts are braced by a screw nut. There are also knownvariants in which the conical interconnecting region is located betweena collar of the screw nut and the receiving opening of the mountingpart. The form of the receiving opening is created in different ways. Ifthe mounting part is made of a die cast metal or plastic, the receivingopening is usually formed during the die-casting or injection molding,whereas it is produced in several drawing steps if sheet metal bentcomponents are involved.

SUMMARY OF THE INVENTION

[0006] In accordance with the present invention, the spring mount of amounting part designed as a sheet metal bent component is formed from asidewall of the u-shaped cross-section profile by deep-drawing. Thus,the sheet metal form part is designed as one piece and includes all theessential functional elements, such as a receiving opening for a wipershaft, a part of a fold-away hinge and a spring mount for an extensionspring. In order to avoid subsequent assembly steps, as many functionsas possible are integrated in one component, which reduces productiontime and cost. Furthermore, there is no contact corrosion in a one-piecemounting part, since there are no critical connecting regions, atriveting pins, for instance.

[0007] For better bracing or introduction of the spring forces in thesidewall of the u-profile, the deep-drawn spring mount has a conicalshape that widens in the direction of the sidewall. As a result, thespring mount has a sturdy design, resulting in minimal elasticdeformation in response to forces, and, in this manner, minimizing, orentirely eliminating, the effect on the application force of the wiperblade.

[0008] The spring mount has a round cross-section. It may also be oval,in which case it is expedient for the larger diameter to point in thedirection of the force of the extension spring when the wiper arm is inthe working position. The cross-section of the spring mount narrows fromthe sidewall to a necking, and then widens again from that point to thefree end. Furthermore, the necking contour is adapted to thecross-section contour of a c-shaped retaining clip, so that theextension spring is securely fastened and will not slide off themounting in response to vibrations. A lateral stop is required to anchorthe extension spring. This is created in a simple manner by compressingthe free end of the spring mount or, in a variant of the presentinvention, by punching and subsequent widening of the end region.

[0009] In order to reduce the friction between the spring mount and thec-shaped clip and thereby the wear resulting from the slight rotation ofthe c-clip during operation, the necking region is expediently providedwith a coating of a bearing material, such as plastic, or an additionalplastic ring. In this manner, the wiper arm can be folded back from thevehicle windshield more easily. The spring mount is preferablydeep-drawn from only one sidewall of the u-profile and projects into theu-shaped cross-section profile, up to its center region. In this manner,a clearance is created adjacent to the spring mount, in which, forinstance, the tube leading to the water supply of a windshield washersystem could be accommodated. Due to the deep-drawn spring mount, avisible insertion point is present on the side of the mounting part,located in a region that is either covered by the articulated part orpossibly by a protective cover. In this context, it is advantageous ifthe spring mount originates from a downward-pointing sidewall of themounting part, for instance pointing towards the vehicle hood, in orderto prevent dirt and water from accumulating in the hollow space of thespring mount which is open to the outside.

[0010] In accordance with the present invention, the spring mount isproduced in several drawing steps. The material is first drawn in over alarge area, so that a uniform wall thickness across all regions isachieved. The conical region is then formed in several steps and acylindrical region at the closed end, as well as the end piece formed asa stop. Since the receiving opening for the wiper shaft is deep-drawnlike the spring mount, both regions may be produced using one tool, inparticular since the production of both regions requires approximatelythe same number of drawing steps (approx. 5 to 7). While this mayslightly increase the cost of the deep-drawing equipment, the machiningtime will not be increased. In this manner, a cost-effective componentis created by producing the two strongly deformed areas of the mountingpart with a comparatively low investment in tool manufacture.

[0011] The receiving opening and the spring mount are best produced inone phase in the still flat metal strip. The characteristic u-profile ofthe mounting part is then produced by bending the sidewalls. After thisreforming process, the spring mount will be located on a sidewall andthe receiving opening for the shaft-hub-connection in the top wall. Ifrequired, the positional accuracy of the spring mount after bending maybe assured in a simple manner in an additional calibration step.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Further advantages result from the following description of thedrawings. The drawings shows exemplary embodiments of the presentinvention. The drawing, the specification and the claims containnumerous features in combination. One skilled in the art will examinethe features not only individually, but also combine them to meaningfulcombinations.

[0013] The figures show:

[0014]FIG. 1: a perspective representation of a mounting part, in topview;

[0015]FIG. 2: one end of the mounting part having a spring mount,enlarged from a different perspective;

[0016] FIGS. 3-5: a part-sectional view of a flat metal part in theregion of the spring mount, during different production phases;

[0017] FIGS. 6-7: Variants of FIG. 5;

[0018]FIG. 8: a cross-section through a mounting part in the region ofthe spring mount, before bending of the sidewalls;

[0019]FIG. 9: a cross-section through a mounting part in the region ofthe spring mount, after bending of the sidewalls; and

[0020]FIG. 10: a section through a receiving opening of the mountingpart.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0021] A mounting part 10 of a windshield wiper is provided at one endwith a receiving opening 12 or 46 for a wiper shaft 44 (FIG. 10) andforms part 14 of a fold-away hinge at the other end (FIG. 1). Mountingpart 10 also has a preformed spring mount 16 at this end, in which ac-shaped clip 18 of an extension spring (not shown) engages. Springmount 16 is formed from a sidewall 24 of the u-shaped cross-sectionprofile 20 by deep-drawing (FIGS. 2 and 9).

[0022] Relatively large tensile forces 64 and 66, respectively, areexerted on spring mount 16 from various directions, via c-shaped clip18. The cross-section of spring mount 16 has a correspondingly sturdydesign, by having a round hollow section which has the largestcross-section in the area transitioning to sidewall 24, and tapers to anecking 34. Necking 34 forms the engagement area of c-shaped clip 18and, therefore, has a contour 36 which is adapted to the cross-sectioncontour of c-shaped clip 18. The cross-section of spring mount 16increases again from necking 34 to the free end, so that a secure seatof c-shaped clip 18 is assured. This is of special importance, sincec-shaped clip 18 executes a relative movement with respect to springmount 16 during the fold-away procedure. In order to reduce the frictionbetween c-shaped clip 18 and spring mount 16, the area of necking 34 isbest coated with a bearing material or surrounded by a ring made ofplastic 70.

[0023] Spring mount 16 is deep-drawn during a phase when sheet 28 isstill flat. In this context, spherical indentation 56 is first formed bymaterial being drawn in over a large area (FIG. 3). A cylindrical part58 is then formed in several steps (FIG. 4). This is compressed inlateral direction 68 by an appropriate tool, thus creating necking 34(FIG. 5). In an exemplary embodiment of the present invention, necking34 is created by punching an opening 60 in the front-side base 38 ofcylindrical part 58, which is widened in a subsequent step (FIGS. 6 and7).

[0024] After forming spring mount 16, the parts of sidewalls 22 and 24are bent in arrow direction 30 and 32, respectively, relative to thepart of top wall 26, u-shaped cross-section profile 20 being formed fromflat sheet 28 (FIGS. 8 and 9). Spring mount 16 will then be located onsidewall 24 and project with its free end into u-shaped cross-sectionprofile 20. Necking 34 has a clearance 42 with respect to profile center40 for laterally fixating the extension spring. This clearance isproduced after bending in an additional calibration step.

[0025] Located on top wall 26 of u-shaped cross-section profile 20 isreceiving opening 12. It has a conical shape, which projects intou-shaped cross-section profile 20 of mounting part 10 and tapers fromtop wall 26 to a collar 62. FIG. 10 shows the mounting region ofmounting part 10, a receiving opening 46 being shown as a variant. Awiper shaft 44 is provided with cone 54 at its free end, which fits intoconical receiving opening 46. Mounting part 10 and wiper shaft 44 arefixedly, but detachably interconnected, by screwing screw nut 50 onto athreaded stud 48. For additional safeguarding of the firm connection,cone 54 is provided with knurling, and a disk 52 is positioned betweenmounting part 10 and screw nut 50. Receiving opening 12 or 46 is bestproduced by deep-drawing. In accordance with the present invention,spring mount 16 is also deep-drawn on mounting part 10, and bothdeep-drawn regions are produced on flat sheet 28 in one phase.

What is claimed is:
 1. A mounting part (10) of a windshield wiper,having a receiving opening (12, 46) for a wiper shaft (44) at one endand forming a part (14) of a hinged joint at the other end, and which isproduced from a flat sheet metal (28) by deep-drawing, punching andbending, having a u-shaped cross-section profile (20) and a spring mount(16), wherein the spring mount (16) is formed by deep-drawing from asidewall (24) of the u-shaped cross-section profile (20).
 2. Themounting part (10) as recited in claim 1, wherein the cross-section ofthe spring mount (16) tapers from the sidewall (24) to a necking (34),und increases in its cross-section from the necking (34) to the freeend.
 3. The mounting part (10) as recited in claim 2, wherein thecontour (36) of the necking (34) is adapted to the cross-section contourof a c-shaped clip (18).
 4. The mounting part (10) as recited in one ofthe preceding claims, wherein a front-side base (38) of the spring mount(16) has an opening (60).
 5. The mounting part (10) as recited in one ofthe preceding claims, wherein the receiving opening (12) widensconically towards a top wall (26) of the u-shaped cross-section profile(20) and at its end pointing into the mounting part (10), has a collar(62).
 6. The mounting part (10) as recited in one of the claims 1through 4, wherein the receiving opening (46) tapers conically towardsthe top wall (26).
 7. The mounting part (10) as recited in one of theprevious claims, wherein the spring mount (16) is coated with a bearingmaterial or is surrounded by a ring (7) of plastic in the region (34)where the c-shaped clip (18) engages.
 8. A method for producing amounting part (10) as recited in one of the preceding claims, whereinthe spring mount (16) is formed initially in the flat sheet metal (28),and the parts of the sidewalls (22, 24) are then bent relative to thepart of the top wall (26).
 9. The method for producing a mounting part(10) as recited in one of the preceding claims, wherein the necking (34)of the spring mount (16) is produced by compression in longitudinaldirection (68).
 10. The method for producing a mounting part (10) asrecited in claim 4, wherein the necking (34) is produced by widening theopening (60) in base (38) of the spring mount (16).
 11. The method asrecited in one of the claims 8 through 10, wherein the receiving opening(12, 46) is produced simultaneously with the spring mount (16), and thesidewalls (22, 24) are bent after this operation.